This study was presented as an oral presentation at the ACVR Annual Meeting, 2010, in Asheville, NC, United States.
VALUE OF TRACHEAL BIFURCATION ANGLE MEASUREMENT AS A RADIOGRAPHIC SIGN OF LEFT ATRIAL ENLARGEMENT IN DOGS
Article first published online: 23 OCT 2011
© 2011 Veterinary Radiology & Ultrasound
Veterinary Radiology & Ultrasound
Volume 53, Issue 1, pages 28–33, January / February 2012
How to Cite
Le Roux, A., Rademacher, N., Saelinger, C., Rodriguez, D., Pariaut, R. and Gaschen, L. (2012), VALUE OF TRACHEAL BIFURCATION ANGLE MEASUREMENT AS A RADIOGRAPHIC SIGN OF LEFT ATRIAL ENLARGEMENT IN DOGS. Veterinary Radiology & Ultrasound, 53: 28–33. doi: 10.1111/j.1740-8261.2011.01871.x
- Issue published online: 25 JAN 2012
- Article first published online: 23 OCT 2011
- Manuscript Accepted: 18 JUL 2011
- Manuscript Received: 23 FEB 2011
- myxomatous mitral valve degeneration;
- tracheal bifurcation angle
An increased tracheal bifurcation angle on the dorsoventral projection is described as a sign of left atrium enlargement in dogs, with a normal range of 60–90° reported. However in people, this angle is a poor indicator of left atrial size. Our purpose was to evaluate the value of the tracheal bifurcation angle for differentiating normal from enlarged left atrium in dogs. Dorsoventral radiographs and echocardiograms of 33 healthy and 73 dogs with confirmed degenerative myxomatous mitral valve disease were evaluated. Left atrial size was classified according to the echocardiographic left atrium to aorta ratio, as normal, mildly, moderately, or severely enlarged. Independent samples t-tests were used to compare the bifurcation angle between groups. A significant difference was observed between the angle of dogs with normal left atrium (68.1 ± 8.5°, range: 51.3–92.4°) and dogs with enlarged left atrium (75.8 ± 8.2°, range: 57.3–91.7°). A significant difference was also noted between the angle of normal dogs and those with moderate (75.5 ± 6.8°, range: 62.8–88.7°) and severe (80.4 ± 7.7°, range: 64.7–91.7°) left atrial enlargement, as well as between dogs with mild (70.7 ± 7.2°, range: 57.3–89.9°) and severe enlargement. Using two discriminators, 85.1° and 76.6°, the bifurcation angle had a specificity of 92.6% and 88.9%, respectively, for identifying left atrial enlargement, and a sensitivity of 15.4% and 40.4%. Although significant differences were observed between dogs with normal and increased left atrial size, the large degree of overlap in the range of bifurcation angles and its poor sensitivity make the measurement of this angle of little value for diagnosing left atrial enlargement.